1. Field of the Invention
This invention relates to a rivet driver for uniting a plurality of plates in a superposed state or for attaching a part to a plate, by driving a rivet therethrough.
2. Description of Prior Art
U.S. Pat. No. 4,131,009 and Japanese Patent Application Disclosure Sho 53(1978)-18069 propose rivet drivers of the type described above. The rivet used with rivet driver disclosed in the U.S. patent comprises a female tube and a male shank upwardly passed inseparably through the female tube so that separate members can be united by inserting the whole rivet through aligned holes in the superposed members, forcibly pulling out the male shank while holding the flange at the upper end of the female tube pressed against the uppermost surface of the superposed members thereby causing the female tube to be radially bent outwardly, and consequently nipping the superposed members between the bent portion of the female tube and the lower side of the flange. Although the rivet driver according to the U.S. patent is hydraulically operated, it cannot be used with a rivet which is designed to unite separate members by driving a male shank into a female tube thereby causing the female tube to be expanded outwardly against the inner walls of the holes in the members.
The rivet driver disclosed in the Disclosure is designed for use with a rivet which unites separate members by driving a male shank into a female tube thereby causing the female tube to be radially expanded outwardly. Since this driver makes use of the force of a spring instead of the pressure of a fluid, it does not operate lightly. The worker using this driver, therefore, is required to exert much energy in operating it so that the work becomes very laborious.